用params重载的C＃方法

Question

Please Help!

What am I doing wrong?

    static void f1(Color color, params float[] f)
    {
        System.Console.WriteLine("Here is f1 for float");
    }

    static void f1(Color color, params int[] f)
    {
        System.Console.WriteLine("Here is f1 for int");
    }

    static void Main()
    {
        f1(null,0);
    }

I can't invoke f1(null,0); I get compile time error.

How this staff can be overcome assuming I indeed need those method signatures?

EDIT: As for Compile-tme error - ReSharper complains:

Cannot resolve method f1(null,int), candidates are:

void f1(Syste.Drawing.Color, params[] float)

void f1(Syste.Drawing.Color, params[] int)

Answer 1

I think the problem is you are passing null for Color which might be upsetting the function, either change that to Color? (since it is a struct) or pass a valid Color value

static void f1(Color? color, params float[] f)

static void f1(Color? color, params int[] f)

Answer 2

You cannot pass null in place of a struct parameter, that is Color in your example. The problem is not about the params parameters. Some valid calls would be like;

f1(Color.Black, 0); // prints "Here is f1 for int"
f1(Color.Black, 0f); //prints "Here is f1 for float"
f1(Color.Black, 0, 5, 6, 7); // prints "Here is f1 for int"
f1(Color.Black, 0, 5.4f, 6, 7); //prints "Here is f1 for float"

Answer 3

If Color is System.Drawing.Color then parameter color can't be null. If you want color to be nullable use Color? type

f1(Color.Black, 0) // works
f1(null, 0) // Doesn't work

Answer 4

您需要在Color参数中传递System.Drawing.Color Object not null。

Answer 5

First of all, you cant use null for the Color parameter. To use one of both codes use this for ints:

f1(SystemColors.ActiveBorder, new int[]{0});

or this for floats:

f1(SystemColors.ActiveBorder, new float[]{0});

the way you use it it will always call the int version.